A 32-year-old woman presents with gum bleeding and petechiae. Hemoglobin is 7.8 g/dL, platelet count 18,000/µL, WBC 21,000/µL with 60% promyelocytes. Some abnormal cells have multiple Auer rods in a single cell. Prothrombin time is prolonged, fibrinogen is 90 mg/dL, and D-dimer is markedly elevated. Which cytogenetic abnormality is expected?
- A inv(16)(p13q22)
- B t(8;21)(q22;q22)
- C t(15;17)(q24;q21) ✓
- D t(9;22)(q34;q11)
Correct answer: C. t(15;17)(q24;q21)
Explanation
The faggot cell, an abnormal promyelocyte packed with multiple Auer rods, together with life-threatening DIC from tissue factor and annexin II release by leukemic promyelocytes, defines acute promyelocytic leukemia. APL results from the PML-RARA fusion of t(15;17), which blocks granulocytic differentiation at the promyelocyte stage and responds to all-trans retinoic acid. inv(16) causes a core binding factor leukemia with monocytic and eosinophilic components, not DIC.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.